🛡️ CVE-2025-40778 on Debian — bind9

Distribution advisory

This page covers CVE-2025-40778 as tracked by Debian, for the package bind9. The fix is available in version 1:9.20.15-1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality none, integrity high, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

• Attack vector: Network — reachable from anywhere that can route to the service.
• Attack complexity: Low — the attack works reliably, with no preparation.
• Privileges required: None — an unauthenticated stranger can try it.
• User interaction: None — nobody has to be tricked into anything.
• Scope: Changed — a successful attack reaches components beyond the vulnerable one.
• Confidentiality impact: None.
• Integrity impact: High — total loss, or loss the attacker controls.
• Availability impact: None.

Weakness class

DEBIAN-CVE-2025-40778 is classified as CWE-349: Acceptance of Extraneous Untrusted Data With Trusted Data. The product, when processing trusted data, accepts any untrusted data that is also included with the trusted data, treating the untrusted data as if it were trusted.

Affected software

DEBIAN-CVE-2025-40778 is recorded against 1 package.

• bind9 (fixed in 1:9.20.15-1)

Timeline and source

Published on 22 October 2025 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

Other advisories for this package

bind9 has other advisories on record. If you are patching this one, these are worth checking on the same host:

• ROOT-OS-DEBIAN-11-CVE-2025-40777 (8.0 High, published 20 Aug 2026)
• ROOT-OS-DEBIAN-11-CVE-2022-2881 (8.0 High, published 20 Aug 2026)
• ECHO-ed2d-c1b0-5e9e (published 23 Jul 2026)
• ECHO-6d4b-e3ee-0962 (published 23 Jul 2026)
• ECHO-6303-1fdb-ed48 (published 23 Jul 2026)
• ECHO-d56a-90b8-201c (published 23 Jul 2026)
• ECHO-fcc4-5d8a-b7af (published 23 Jul 2026)
• ECHO-d176-cede-4ce1 (published 23 Jul 2026)

Same weakness in other software

These advisories are the same class of weakness (CWE-349: Acceptance of Extraneous Untrusted Data With Trusted Data) in other software:

• CVE-2026-50252 (9.3 Critical, published 22 Jul 2026)
• CVE-2024-53848 (7.1 High, published 7 Jul 2026)
• CVE-2026-41120 (9.8 Critical, published 25 Jun 2026)
• CVE-2026-33612 (7.5 High, published 25 Jun 2026)
• CVE-2026-45602 (9.1 Critical, published 9 Jun 2026)
• CVE-2026-42960 (10.0 Critical, published 20 May 2026)
• CVE-2026-46342 (2.0 Low, published 19 May 2026)
• CVE-2026-44572 (3.7 Low, published 13 May 2026)

CVE-2025-40778 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Affected Packages

References